sci.op-research

HI,
I have a MIP to locate facilities in network. I would like to
formulate in cplex 6.0.Could you help me please!!


sets:
I: customer
J: plant1
K: plant2
K':plant3
T: period

param C[i in I, j in J, t in T] : transport cost from i to j in period
t
param C[j in J, k in K, t in T] : transport cost from j to k in period
t
param C[j in J, k' in K', t in T] : transport cost from j to k' in
period t
param C[j in J, k in K, t in T] : variable cost from j to k in period
t
param C[j in J, k in K, t in T] : variable cost from j to k in period
t
param C[j in i, j in J, t in T] : variable cost from j to k' in
period t
param F[j in J, t in T] : fixed cost of installing j in period t
param F[k in K,t in T] : fixed cost of installing k in period t
param F [k' in K', t in T] : fixed cost of installing k' in period t


var X[i,j,t]: quantity of product from i to j in period t
var X[j,k,t] : quantity of product from j to k in period t
var X[j,k',t] : quantity of product from j to k' in period t
binary variables:
y[j,t]=1 if j is open, =0 otherrwise
z[k,t]=1 if k is open , =0 otherwise
W[k',t]=1 if k' is open, =0 otherwise

objectif fonction:
Min Q =sum (j in J, t in ) F[j,t] * Y[j,t] + sum (k in K, t inT) Z[k,
t ] * F[k,t] + sum(k',t) F[k',t] * W[k',t] + sum(i,j,t) C[i,j,t] * X
[i,j,t] + sum(j,k,t) C[j,k,t] * X[j,k,t] +sum(j,k',t) C[j,k',t] *
X[j,k',t]
subject to:
sum(j) X[]i,j,t] =1
20% sum(j)X[i,j,t] <= X[j,k,t]
sum(j) X[i,j,t] <= Y[j,t]
X[i,j,t] >=0
X[j,k,t]>=0
X[j,k',t]>=0
0<=Y[j,t]<=1
0<=Z[k,t]<=1
0<=W[k',t]<=1
Thanks all lot.